The Bootes Void

In the course of a redshift survey of galaxies brighter than R approximately equal to 16.3, 133 redshifts were measured in three fields, each separated by roughly 35 deg from the other two. If the galaxies in these fields were distributed uniformly, the combination of a galaxian luminosity function and the magnitude limits predicts that the distribution of redshifts should peak near 15,000 km/s. In fact, only one galaxy of the 133 was observed with a redshift in the 6000 km/s interval centered on 15,000 km/s. One plausible interpretation is that a large volume in this region of order 1,000,000 cu Mpc is nearly devoid of galaxies.

Oemler A., Jr., Schechter P. L., Kirshner R. P., Shectman S. A., A million cubic megaparsec void in Bootes (1981)

• astronomy
• wonder